A conventional feeding device with feeding rollers is generally employed for feeding an elongated workpiece to be machined, such as a wood or metal plate. To maintain a stable feeding movement of a workpiece with an uneven configuration, each feeding roller is coupled with and driven by an individual transmitting unit which is pivotably mounted on a feeding machine so as to provide a constant urging force by means of a spring to permit each feeding roller to continually press a workpiece during a feeding process. However, the transmitting units are complicated in construction, which results in high manufacturing and maintenance costs.
Another transmission construction for feeding rollers of a feeding machine disclosed in Chinese Patent No. 203754045U is provided with chain and gear assemblies for transmitting a power of a motor to two driving shafts of two transmitting roller units, which simultaneously rotate two feeding rollers of each transmitting roller unit. However, the two feeding rollers could rotate at different speeds when a workpiece of uneven thickness is fed, thereby adversely affecting the machining process thereof. Besides, two turnable mounting bodies disposed between a driving shaft of each transmitting roller unit and two roller shafts for a spring to be abutted thereagainst are needed for performing a pressing and feeding work, which results in restriction of the dimension and application of the feeding machine.